Question
Question: If $a + b + c = 0$, then the value of $\frac{a^2(b+c)+b^2(c+a)+c^2(a+b)}{abc}$ is...
If a+b+c=0, then the value of abca2(b+c)+b2(c+a)+c2(a+b) is

A
3
B
-3
C
−31
D
31
Answer
-3
Explanation
Solution
Given the condition a+b+c=0. We want to find the value of the expression abca2(b+c)+b2(c+a)+c2(a+b).
From a+b+c=0, we have: b+c=−a c+a=−b a+b=−c
Substitute these into the numerator: Numerator = a2(b+c)+b2(c+a)+c2(a+b)=a2(−a)+b2(−b)+c2(−c)=−a3−b3−c3=−(a3+b3+c3)
Using the algebraic identity: a3+b3+c3−3abc=(a+b+c)(a2+b2+c2−ab−bc−ca)
Since a+b+c=0, we have: a3+b3+c3−3abc=0 a3+b3+c3=3abc
Substitute this back into the numerator: Numerator = −(a3+b3+c3)=−(3abc)
So the expression becomes: abc−(3abc)=−3, assuming abc=0.
Therefore, the value of the expression is -3.